I'm assuming you're comparing two triangles? If not, then this is probably wrong.
Triangle = 180 degrees
180 divided by 3 = 60 degrees
since ∠1 ≅ ∠2 ≅ ∠3, each angle equal 60 degrees
∠4 ≅ ∠5
m∠4 = m∠3 + 10
m∠3 + 10 = m∠5
we know that m∠3 is 60 degrees.
60 + 10 = 70, so m∠5 is 70 degrees
70 degrees is the answer.
